The end, at least, looks familiar, with an intense focus on the now-familiar cast of competitive states: Florida, Ohio, Pennsylvania, Iowa, Nevada, North Carolina.

Donald Trump and Hillary Clinton even have engaged in the time-tested ritual of "trying to expand the map," visiting and advertising in a couple of just-out-of-reach states - Wisconsin and Michigan for the Republican, Arizona and Georgia for the Democrat. In Nevada on Saturday night, Trump was rushed off the stage in a brief security scare before returning to finish his speech.

For the most part, Campaign 2016 has looked like a reality TV show plotted by a screenwriter on mescaline - absurd, unlike any presidential election before it. Historians and political scientists will puzzle over this long, strange trip for years.

Consider:

It was the first U.S. election in which a candidate was captured on tape talking about grabbing women by the genitals and also the first in which a candidate vowed to throw his opponent in jail if he should win, as Trump did in the second debate.

It was the first election with a woman as the major-party nominee. She also is the first nominee under FBI investigation as the polls are about to open, for mishandling classified material on an unsecured private email server when she was secretary of state.

It was the first election in which a candidate said he might not accept the outcome if he loses. Trump has said the system is rigged against him. "I will look at it at the time," he said in the third debate last month. "I'll keep you in suspense."

Not to mention, it was the first modern campaign in which one candidate, Trump, relied mostly on holding big campaign events and trying to drive news coverage. He even financed some of his campaign himself. Clinton, by contrast, raised billions from donors and has taken an analytic approach, using big data to target supporters and get them to vote. The campaign and its allies also have outspent Trump 2-1 on television advertising in battleground states.

Trump and Clinton are the most disliked presidential candidates ever recorded in public-opinion polling, and those ratings have only been reinforced by their campaigns of relentless attacks against each other.

Conventional wisdom says all that negativity tends to depress voter turnout, but pollsters looking at indicators of intense interest in the race say that might not be true this time, as people will be motivated to vote against the person they most detest. If that happens, it would upend decades of social-science research.

In the last week, national and battleground polls seemed to tighten. And while many circumstances of the campaign are unique - there has never been a presidential candidate like Trump, a businessman and reality TV star with zero experience in politics, for instance - the polarization it has inspired is recognizable.

"This campaign is something that's been a long time coming," said J. Wesley Leckrone, a political scientist at Widener University. "We've started reaping the rewards of trends like people getting their news content only from sources they agree with, and segregating themselves politically, with rural areas becoming more Republican and urban areas more Democratic. All that is affecting this election and will continue to influence elections for some time."

In the Manichaean view, many Democrats say that Trump and the GOP would roll back same-sex marriage and end abortion rights. It's easy to find Republican voters sincerely convinced Clinton would confiscate their guns.

"The problem is that when you view all politics as a zero-sum game, where my way of life is threatened by you being in power, then there's no room for the compromises necessary for democracy," Leckrone said.

To Tabatha Abu El-Haj, a Drexel University law professor, the voter dissatisfaction that gave rise to both Trump and Democratic primary challenger Sen. Bernie Sanders of Vermont was driven by the same force.

"There is a bipartisan concern that political leaders are not representing their constituents - they are playing to the base by engaging in partisan wrangling, or doing what their campaign donors want rather than governance, addressing problems the country has," said Abu El-Haj, who has researched barriers to political participation.

She said that a long-term decline of membership in broad-based civic groups such as labor unions, the American Legion, and even churches has diminished ordinary Americans' connections to political institutions. In addition, she said, party organizations have weakened following the Citizens United Supreme Court decision, which has allowed unlimited donations to independent super PACs.

And the result of all these 2016 peculiarities?

Eighty-two percent of voters in a CBS/New York Times poll released Thursday say they are "disgusted" by the campaign; only 13 percent said they were excited to cast their ballots.

@tomfitzgerald www.inquirer.com/bigtent